REPLACING HEAD GASKET NEED HELP

1991 Pontiac Sunbird • 50,000 miles

I am replacing my head gasket on my 91 Pontiac Sunbird LE. It has a 2.0 L engine. Also, its a convertible(im not sure if the convertible edition is different from the regular) and I am wondering if there is anything I should replace besides the gasket, refilling the oil and coolant after draining, and the bolts that you generally replace. Any help will be greatly appreciated.

While the engine was off, I did an oil change. And frsh oil began running out of the muffler. I did a compression test and they were all low but one was severely low. So, I assume it to be head gasket.